JP3074853B2 - Inductance component and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inductance component having a magnetic material, and more particularly to a thin inductance component having excellent characteristics and a method of manufacturing the same.

[0002]

2. Description of the Related Art Inductance components are widely used as coils, transformers and the like of various communication devices and consumer devices, and in recent years, small or thin inductance components have been increasingly required.

As a small-sized inductance component, a multilayer inductor (for example, Japanese Patent Application Laid-Open No. 55-91103) in which magnetic layers and conductors are alternately stacked, a multilayer transformer having a similar structure, and the like have been proposed. At present, a limited ferrite magnetic material that can be sintered at a low temperature, for example, a NiZnCu-based ferrite, is used because it is obtained by simultaneously firing a ferrite magnetic material and a conductor. Other ferrite magnetic materials having excellent magnetic properties such as magnetic permeability or magnetic flux density for miniaturization and the like, for example, Mn
Zn-based ferrite cannot be used. On the other hand, as an inductance component obtained by applying a winding or the like to a ferrite magnetic material sintered under sufficient conditions, a ferrite magnetic material that is sintered alone is used. Therefore, various types of ferrite magnetic materials can be used, and excellent magnetic properties of ferrite magnetic materials can be utilized. But,
There is a limit to miniaturization, especially to a reduction in thickness, and moreover, it is common to use a coated copper wire for the winding, and therefore there is a limit to the heat resistance.

[0004]

As described above, various inductance components have been proposed.
Uses the properties of various types of ferrite magnetic materials to their fullest extent, and is compact or thin, and is compact and highly integrated with various modules using inductance components, or is mounted on a wiring board and inductance components. However, there has been a problem that an inductance component that satisfies a manufacturing process or the like in which the above-described processes are simultaneously performed has not been obtained.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems. Various types of modules using a ferrite magnetic material of various types, which exhibit sufficient magnetic properties, are thin or small, and use inductance components are provided. It is an object of the present invention to provide an inductance component that satisfies miniaturization, high integration, and the like.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has a coil having an insulating layer and a conductor portion alternately laminated on a ceramic substrate, and further has a coil which is not in contact with the ceramic substrate or is not required. It is an inductance component having a magnetic material separated by a gap or a pair of magnetic materials separated by a necessary gap or contacting through a through hole of a ceramic substrate.

[0007]

According to the above-mentioned inductance component, a coil composed of a ceramic or the like and a metal formed by alternately laminating an insulating layer and a conductor portion on a ceramic substrate is provided. Inductors with a pair of magnetic bodies separated from each other by a magnetic substance or through a through hole in a ceramic substrate, or a pair of magnetic substances separated by a necessary gap, make up the majority of the magnetic circuit with magnetic substances. Soft magnetic characteristics can be sufficiently exhibited. For example, if the magnetic material is ferrite, the magnetic properties of various ferrite magnetic materials can be sufficiently exhibited. In addition, since the coil is formed by alternately laminating the insulating layers and the conductors, it becomes a thin or small inductance component. Furthermore, since the inductance component is made of a material having sufficient heat resistance, heat resistance and reliability can be ensured, and an inductance component that enables a manufacturing process and the like in which the wiring board and the inductance component are simultaneously mounted is realized. Become.

[0008]

An embodiment of the present invention will be described below.

The inductance component of the present invention has a coil in which insulating layers and conductors are alternately laminated on a ceramic substrate (in some cases, a ferrite magnetic layer is provided between the ceramic substrate and the coil), and furthermore, a ceramic. It is an inductance component having a magnetic material that is in contact with a substrate (in some cases, a ferrite magnetic layer) or a required gap or a pair of magnetic materials that is in contact with or through a required gap through a through hole of a ceramic substrate. Thus, the inductance component of the present invention can be roughly divided into three parts. One is composed of a ceramic substrate, a magnetic body, and a coil. The coil is further composed of at least two parts, an insulating layer and a conductor. The second is composed of a ceramic substrate, a pair of magnetic materials and a coil, and the third is an inductance component composed of a ceramic substrate, a ferrite magnetic layer, a coil and a magnetic material.

The ceramic substrate refers to a general ceramic substrate, and the most frequently used one is an alumina substrate. In some cases, it is more advantageous to use a magnetic substrate such as a ferrite substrate than to use a nonmagnetic substrate such as an alumina substrate. This is effective because the ferrite substrate forms a part of the magnetic circuit and the thickness of the inductance component is reduced, and the inductance is improved or the magnetic shielding property is improved. The magnetic material refers to a magnetic material having excellent soft magnetic properties. Particularly, a magnetic material of an oxide and a ferrite sintered body having good compatibility with the inductance component of the present invention. The insulating layer forming the coil includes glass having electrical insulating properties, glass containing oxides or raw materials for various ceramic substrates, and the like. Any material having high electrical insulating properties may be used. The conductor material refers to a material having excellent conductivity. As described in detail in the production method of the present invention, a ferrite magnetic layer refers to a layer in which ferrite powders are bonded to each other or bonded with another low melting point material, unlike the above-described magnetic material, and have relatively many holes. It is an existing layer. For example,
When the magnetic material is a ferrite sintered body, the difference from the ferrite magnetic layer is that the ferrite sintered body is made of various types of spinel-type ferrites which are generally known to remove a small amount of additives. , Very high density with few holes and the like. On the other hand, the ferrite magnetic layer is a layer containing a low-melting binder such as glass in the case of ferrite having a large number of pores and a high sintering temperature, like the ferrite layer of the above-described laminated inductor.

As a manufacturing method, there is provided a method in which an insulating layer and a conductor portion are alternately laminated on a ceramic substrate to form a coil, and a magnetic material is fixed on the ceramic substrate before or after firing the coil. Form a coil on a magnetic material,
A method of fixing the magnetic body and the ceramic substrate before or after firing the coil, forming a coil on the ceramic substrate, and before or after firing the coil, a pair of magnetic bodies is passed through the through hole of the ceramic substrate. A method of fixing and obtaining a coil on one of a pair of magnetic bodies, and a method of fixing the coil to the other magnetic body through a through hole of the ceramic substrate before or after firing the coil or the ceramic substrate There is a method in which a ferrite magnetic layer is formed thereon, a coil is formed thereon, and a magnetic material is fixed to the ferrite magnetic layer before or after firing of the ferrite magnetic layer and the coil.

The conductor portion or the insulating layer constituting the coil can be formed by a printing method, a dipping method, a spin coating method, or the like, and a laser or the like can be used to form the conductor pattern. That is, this method is to form a coil by forming a conductor layer on the entire surface and then removing a part of the conductor layer with a laser. The ferrite magnetic layer is similarly formed by printing or the like. These may be a generally known method of forming each layer directly on a ceramic substrate or a magnetic material, or a method of laminating green sheet-like layers. Furthermore, there is a method in which mica or a very thin insulator plate is used as an insulating layer, and a conductor pattern is formed on the mica or the insulating plate by printing or the like to produce a coil.

A specific example of the inductance component of the present invention will be described in more detail with reference to the drawings. 1 (a), (b), FIG.
3 (a) and 3 (b) and FIGS. 3 (a) and 3 (b) show an exploded perspective view of a typical inductance component of the present invention and a schematic view of a cross section of a coil portion. FIGS. 1, 2 and 3 show three typical types of inductance components of the present invention. 1, 2 and 3, 1 is a ceramic substrate, 2 is an E-type or EI-type magnetic material, and 3 is a ferrite magnetic layer. Reference numeral 4 denotes an insulating layer, and reference numeral 5 denotes a conductor. A coil is formed by the insulating layer 4 and the conductor 5. The conductor portion 5 may be composed of any number of layers.

The ceramic substrate 1 is a generally known ceramic substrate, and includes various ceramic substrates such as alumina, mullite, beryllia, steatite, forsterite, magnesia, titania, and ferrite.

As the magnetic material 2, there are magnetic materials such as ferrite magnetic material, permalloy, sendust and the like having excellent soft magnetic properties such as oxide or metal.

The ferrite magnetic layer 3 includes various spinel-type ferrites or mixtures other than MnZn-based ferrite, NiZn-based ferrite, and NiZnCu-based ferrite. Since the conditions are significantly different, differences occur in the structure, magnetic characteristics, and the like.

As the material for forming the insulating layer 4, various ceramics or various glass ceramics, nitrides, carbides, Ni
Examples include Zn-based ferrite, NiZnCu-based ferrite, and mica. In the present invention, the insulating layer 4 is referred to as an insulating layer. However, the insulating layer 4 may be formed of a material other than an insulator, such as a dielectric or a non-magnetic material, as long as the material has a high electric resistance. Examples of the dielectric include those contained in the aforementioned insulator, barium titanate, potassium niobate, and the like. Examples of the non-magnetic material include zinc ferrite and iron oxide which are compatible with spinel ferrite.

Examples of the material of the conductor 5 include silver, copper, gold, an alloy of silver and palladium, and an alloy of silver and platinum, which are commonly used in a printing method or the like. The resistance and melting point of the conductor are important conditions for selection.

As described above, the ceramic substrate 1, the magnetic material 2, the ferrite magnetic layer 3, the insulating layer 4, and the conductor 5 need not necessarily be formed of one material, but may be formed of a mixture of various materials. Good. As described above, by forming an inductance component including the ceramic substrate 1, the magnetic material 2, the ferrite magnetic layer 3, and the coil (consisting of the insulating layer 4 and the conductor portion 5), a thin or ferrite sintered body having sufficient characteristics can be obtained. A small inductance component can be obtained. Since all or most of the magnetic circuit is made of a ferrite sintered body, it is an inductance component which is thin or small and has excellent electrical characteristics. When using a ceramic substrate to manufacture one electrical module, for example, a DC-DC converter, etc., when using a thick-film resistor or capacitor, etc., the features of the inductance component of the present invention can be further exhibited. It is possible to obtain a manufacturing process or a high-density mounting in which the wiring board and the inductance component of the present invention are mounted at a time, and also to obtain high reliability.

As the shape of the coil, a solenoid type or a planar coil such as a spiral having multiple turns on the same surface is typical. The solenoid type is effective for miniaturization, and the spiral type is effective for thin type. It is.

Ferrite magnetic layer 3, insulating layer 4, and conductor 5
The paste for forming the powder is prepared by mixing each powder with a solvent such as butyl carbitol, terpineol and alcohol, a binder such as ethyl cellulose, polyvinyl butyral, polyvinyl alcohol, polyethylene oxide, ethylene-vinyl acetate, and various oxides or glass. Sintering aids such as butyl benzyl phthalate,
A plasticizer such as dibutyl phthalate or glycerin or a dispersant may be added. Each layer is formed using a kneaded material obtained by mixing these. These are laminated in a predetermined structure as described above, and are fired at a predetermined temperature to obtain an inductance component.

The firing temperature range is about 700 ° C. to 13 ° C.
It is in the range of 00 ° C. In particular, it differs depending on the constituent material of the conductor forming the coil. For example, if silver is used as the conductor material, the temperature needs to be relatively low, and an alloy of silver and palladium can be used at a relatively high temperature.

Next, more specific embodiments of the present invention will be described. (Example 1) 20 g of glass powder having a firing temperature of 850 ° C
Then, 6 g of a mixture of terpineol and ethyl cellulose in a weight ratio of 100: 6 (hereinafter abbreviated as binder) was added and mixed, and then kneaded using a three-roll mill to prepare a glass paste. 30 more silver powder
g and 3 g of a binder were used to prepare a silver paste in the same manner. Using these pastes, the substrate insulating pattern shown in FIG. 4A was formed on a MnZn-based ferrite substrate, a NiZn-based ferrite substrate, and a 96% alumina substrate having a length and width of 50 mm and a thickness of 1 mm by a screen printing method. Printed using. Next, the coil A pattern shown in FIG. 4B was printed using a silver paste, and the insulating pattern shown in FIG. 4C was printed thereon using a glass paste. Further, the coil B shown in FIG.
The pattern was printed with silver paste, and the inter-coil insulating patterns shown in FIG. 4E were sequentially printed using glass paste to form coils. Drying after printing was performed at 150 ° C., and each layer was printed twice to form a coil. The plate used for printing is made of stainless steel and has a mesh of 200. The coil is the same as the coil A pattern shown in FIG.
And the two layers of the coil B pattern shown in FIG. Figure 4 on coil A pattern
When the insulating pattern shown in (c) is printed, the center portion (the portion where the line is thickened) of the coil A pattern is exposed, and when the coil B pattern is printed thereon, both are connected at the exposed portion. .

Next, a MnZn ferrite E-type core (E
The foot length of the mold core is 0.2 mm and the thickness of the back of the core is 1 mm. After the lath paste is applied to the contact portion with the substrate, the ferrite E-type core is brought into contact with the substrate through this glass, and the ferrite substrate and the alumina substrate are held at 850 ° C. in the atmosphere for 10 minutes. It was fired under the condition of cooling in nitrogen.

Next, the inductance of the inductor obtained by firing was measured. The measurement was performed using an LCR meter, and the measurement frequency was 500 kHz. 200 μH for a MnZn ferrite substrate, 150 μH for a NiZn ferrite substrate, and 50 μH for an alumina substrate.
Met.

As described above, the inductor according to the present invention is an inductance component exhibiting excellent electrical characteristics. Further, although the E-type core of the ferrite sintered body is used, the inductor is thin and has a low heat resistance because it is manufactured by a thick film process. It was an abundant inductance component that fully exhibited the magnetic properties of the sintered ferrite magnetic material.

Example 2 A glass paste was prepared by adding 6 g of a binder to 20 g of a glass powder having a firing temperature of 950 ° C., mixing and kneading the mixture. Using the same three types of substrates as in Example 1, in the same manner as in Example 1, substrate insulation, coil A pattern, insulation pattern, coil B pattern, and inter-coil insulation pattern were sequentially printed. The same silver paste as in Example 1 was used. And coil A
The above-mentioned printing (coil A pattern, insulation pattern, coil B pattern, and inter-coil insulation) is repeated using the same coil pattern (C to H) having a different coil terminal position from the pattern or coil B. As shown in FIG. 5, five coils were stacked using six types of C to H coil patterns other than the coil B.
FIG. 5 is a diagram schematically showing a cross section of the coil portion, wherein A to H indicate that the lead wires and terminal positions of the coil are different, and 11 to 14 indicate the coil numbers. Coil 12 is 2
One means that two coils are connected in parallel to form one coil because the terminal positions match. One coil is formed by A and B, and one coil is formed by C and D in the same manner. doing.

Next, a glass paste was applied to the contact portion of the M-Zn ferrite E-type core (the E-type core had a foot length of 0.6 mm and the back of the core had a thickness of 1 mm) with the substrate. The ferrite substrate and the alumina substrate were kept at 850 ° C. for 10 minutes in the atmosphere by coating and bringing the E-shaped core into contact with the substrate via this glass, and then fired under the condition of cooling in nitrogen. Thus, the glass paste was applied between the substrate and the E-shaped core, and both were fixed and a gap was formed.

An inductance component having four coils built therein, that is, a transformer, was measured in the same manner. The inductance of the coil 12 is MnZ
200 μH for an n-type ferrite substrate,
It was 150 μH for an n-based ferrite substrate and 50 μH for an alumina substrate.

Further, when the coil 11, the coil 13, or the coil 14 other than the coil 12 was opened or short-circuited, and the coupling state of the coil was obtained as a coupling coefficient, when the coil 11 or the coil 14 was short-circuited, both were 0.998. The value was 0.999 when the coil 13 was short-circuited. Thus, the inductance component of the present invention exhibited excellent characteristics with little leakage magnetic flux even as a transformer.

(Embodiment 3) Thickness of 0.02 to 0.03
Using a plurality of mica plates of mm, the coil A pattern and the coil B shown in FIG.
Printing was carried out using the silver paste prepared in the above. The insertion hole of the E-shaped core was formed in this mica plate using a carbon dioxide laser. The mica having the coil A pattern and the coil B formed thereon was overlapped and connected at the center using a silver paste.

Next, the mica and MnZn-based ferrite E-type cores were fixed to the same three types of substrates as in Example 1 using a glass paste, and these were fixed at 850 ° C. in air for 2 hours.
After holding for 0 minutes, firing was carried out under cooling conditions in nitrogen.

When the inductance was measured in the same manner as before, the inductance was 200 μm for the MnZn-based ferrite substrate.
H, 150 μH for the NiZn-based ferrite substrate, and 50 μH for the alumina substrate.

Example 4 6 g of a binder was added to 20 g of a glass powder having a firing temperature of 880 ° C., mixed, and kneaded to prepare a glass paste. Using the same three types of substrates as in Example 1, the entire pattern shown in FIG. 6 was printed on each substrate using a glass paste. Next, in the same manner as in Example 1, the coil A pattern, the insulating pattern, the coil B pattern, and the inter-coil insulation were sequentially printed. The same silver paste as in Example 1 was used. Further, similarly to the second embodiment, using the same coil pattern (C to H) having a different coil terminal position from the coil pattern A or the coil B, the printing (coil A pattern, insulating pattern, coil B pattern, coil Insulation) was repeated, that is, five coils were laminated as shown in FIG. 5 in the same manner as in Example 2 using six types of C to H coil patterns other than the coil A and the coil B.

Next, an E-type core of MnZn-based ferrite (the foot length of the E-type core is 0.6 mm and the thickness of the back of the core is 1 mm) is inserted into the insertion hole of the core. 850 ferrite and alumina substrates in air
After holding at 10 ° C. for 10 minutes, firing was performed under cooling conditions in nitrogen. As described above, the E-type core and the substrate were fixed and a gap was formed by printing the entire surface pattern shown in FIG. 6 on the substrate.

The inductance was measured as before. The inductance of the coil 12 was 200 μH in the case of the MnZn-based ferrite substrate, 150 μH in the case of the NiZn-based ferrite substrate, and 50 μH in the case of the alumina substrate, which was equivalent to that of Example 2.

Further, when the coil 11 other than the coil 12, the coil 13, or the coil 14 was opened or short-circuited, and the coupling state of the coil was obtained as a coupling coefficient, when the coil 11 or the coil 14 was short-circuited, both were 0.998. The value was 0.999 when the coil 13 was short-circuited. Thus, the inductance component of the present invention exhibited excellent characteristics with little leakage magnetic flux even as a transformer.

(Embodiment 5) The ferrite E-shaped core as shown in FIG.
Using a 96% alumina substrate having a thickness of 0 mm and a thickness of 0.635 mm, a coil was formed on the alumina substrate using the same method and the same paste as in Example 1.

Next, an E-type core of MnZn-based ferrite (the foot length of the E-type core is 0.8 mm and the thickness of the spine of the core is 1 mm) and the I-type core having a thickness of 1 mm are described. A glass paste is applied to the contact portion, and the ferrite E-type core and the I-type core are brought into contact with each other through a foot through an insertion hole of the alumina substrate. The ferrite core and the alumina substrate are held at 850 ° C. in the atmosphere for 10 minutes. It was baked under cooling conditions.

When the inductance was measured in the same manner as before, it was 200 μH. Unlike the first embodiment, the inductor of the present embodiment uses a commonly used alumina substrate and exhibits very excellent inductance.

Using a similar alumina substrate, a transformer was prototyped in the same manner as in Example 2, but the same characteristics as those obtained when a ferrite substrate was used were obtained.

Example 6 20 g of NiZnCu-based ferrite powder and 7 g of binder were mixed and kneaded.
An iZnCu-based ferrite paste was prepared.

On an alumina substrate having a length of 50 mm and a width of 1 mm, the entire pattern shown in FIG. 6 was dried to a thickness of 0.5 mm using a NiZnCu-based ferrite paste.
Printed first until mm. Next, a coil was formed in the same manner as in Example 1 using the glass paste and the silver paste prepared in Example 1. Printing was performed according to the procedure described in Example 1.

Next, after holding at 850 ° C. in the atmosphere for 10 minutes, the mixture was fired under the condition of cooling in a nitrogen atmosphere.

When the inductance was measured in the same manner as before, it was 80 μH.

[0046]

According to the present invention, there is provided a coil having an insulating layer and a conductor alternately laminated on a ceramic substrate, and a magnetic material or a through hole of the ceramic substrate which is in contact with the ceramic substrate or with a necessary gap. Through the use of an inductance component that has a pair of magnetic bodies separated by a contact or a necessary gap through it, the majority of the magnetic circuit is composed of magnetic bodies, and sintering of various systems that exhibited sufficient magnetic properties as magnetic bodies Ferrite magnetic material can be used,
It becomes an inductance component having very excellent characteristics.
Furthermore, since the coil height is small because the coil is a thick-film coil in which insulating layers and conductor layers are alternately laminated, a very thin or small inductance component is obtained. Furthermore, the present invention provides an excellent inductance component having both sufficient heat resistance and high reliability.

[Brief description of the drawings]

1A and 1B are an exploded perspective view showing a configuration of a typical inductance component of the present invention and a cross-sectional view of a coil part.

FIGS. 2A and 2B are an exploded perspective view showing a configuration of a typical inductance component of the present invention and a cross-sectional view of a coil portion.

3A and 3B are an exploded perspective view showing a configuration of a typical inductance component of the present invention and a cross-sectional view of a coil part.

FIGS. 4A to 4E are diagrams showing each pattern for forming a coil in the embodiment.

FIG. 5 is a schematic cross-sectional view showing a stacked state of coils in an example.

FIG. 6 is a view showing an entire surface pattern in the embodiment.

[Explanation of symbols]

 Reference Signs List 1 ceramic substrate 2 magnetic body 3 ferrite magnetic layer 4 insulating layer 5 conductor

──────────────────────────────────────────────────続 き Continuation of the front page (72) Hiroyuki Handa 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-55-91103 (JP, A) 14768 (JP, U) Real opening 58-173212 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01F 17/00-17/04 H01F 41/00, 41/04

Claims (2)

(57) [Claims] 1. A ferrite magnetic layer on a ceramic substrate, and further comprising a coil formed by alternately laminating an insulating layer and a conductor portion on the ferrite magnetic layer. An inductance component having a body. 2. A ferrite magnetic layer is formed on a ceramic substrate, and a coil formed by alternately laminating an insulating layer and a conductor is formed on the ferrite magnetic layer. A method of manufacturing an inductance component obtained by fixing a body on a ferrite magnetic layer.